Eight years after the tea party movement helped Republicans win a majority of U.S. governorships, the GOP is bracing for a potential power shift that would reshape the nation’s political landscape.

The long winning streak has given Republicans control of the governor’s office in 33 states, the most since 1928. And the party is defending 26 of them in November -- nearly three times as many as Democrats -- in a midterm election widely seen as a referendum on the presidency of Donald Trump.

For Republicans, the numbers alone spell trouble, said Jennifer Duffy, an analyst with The Cook Political Report in Washington. “They had nowhere to go but down,” she said. “Their entire objective this cycle was to minimize the damage.”

The elections will test whether Democrats have lost the Midwest for the foreseeable future and whether Trump’s touch can hold back the effects of a growing minority electorate in the South. They’ll also gauge the nation’s gender dynamics: A record number of women are running for governor in a year marked by both the Me Too movement and the Brett Kavanaugh Supreme Court confirmation fight.

‘Strong Gerrymanders’

A new crop of Democratic governors could do more than change state policy direction. It could help determine the makeup of the U.S. Congress for the next decade. Governors elected this year will have a strong influence on the redrawing of congressional district maps after the 2020 census. Twenty-nine of the governors on this year’s ballot will have vetoes over redistricting maps in 2021, according to the National Conference of State Legislatures.

After 2010, when Republicans took control of statehouses and governors mansions in droves, they shut Democrats out of the redistricting process, said James Battista, a political science professor at the University of Buffalo. “You ended up with a fair number of states putting in place really strong gerrymanders to minimize Democratic influence,' he said.

Those Tea Party-era districts were more aggressively gerrymandered and more durable than usual, since they also made it harder for Democrats to win back control of the legislatures responsible for drawing subsequent maps, said Michael Li, senior counsel for the Brennan Center for Justice’s Democracy Program.

The math for governors is a mirror image of the numbers that make Democratic control of the Senate an uphill fight. Of 36 gubernatorial offices on the ballot next month, one is held by an independent who dropped out of the race, nine by Democrats and 26 by Republicans. In the Senate races, Democrats are defending 26 seats and Republicans nine. Another complication for Republican governors is term limits: Of the 17 races with no incumbent, 13 are currently held by Republicans.

Twelve GOP-held governorships are clearly in play, according to Cook report rankings, including three that appear to be tilting toward Democrats and nine that are too close to call. Only two of nine races for Democrat-held seats are competitive. In one, Connecticut, Republican Bob Stefanowski, a former company officer at General Electric Corp., is running neck-and-neck with Democrat Ned Lamont, a telecommunications executive, to succeed Dannel Malloy, who isn’t running for a third term.

Other cliffhangers include four Midwestern states where Hillary Clinton saw her presidential hopes evaporate in 2016. Two have no incumbent. If Democrats don’t win some of them, it would send a chilling message about the party’s prospects in 2020.

Tea Party Icon

Among the vulnerable: Tea Party icon Scott Walker of Wisconsin, which chose Trump by less than 23,000 votes, picking a Republican president for the first time since 1984. Walker has dominated Wisconsin state politics for eight years, winning three times, including in a recall vote. Now running for a third term, he’s neck-and-neck with Democratic state schools superintendent Tony Evers, according to the Cook report and Real Clear Politics poll averages.

Democratic gubernatorial candidates are also competitive in Ohio and Iowa, two states that chose Trump by 8 and 9 percent margins, respectively. In Michigan, where he squeaked out a surprise win by 10,704 votes, the Democrat is favored.

Ohio’s popular Republican Governor John Kasich can’t run again. Republican Attorney General Mike DeWine and Democrat Richard Cordray, former head of the Consumer Financial Protection Bureau, are essentially tied, in what’s been dubbed the “battle of the bland.” The contenders are “two of the least charismatic candidates I’ve ever met,” said Cook’s Duffy.

In Iowa, incumbent Republican Kim Reynolds’s race is too close to call, despite Trump’s blowout two years ago. In Michigan, Democrat Gretchen Whitmer is on track to win the seat held for eight years by Republican Rick Snyder, who isn’t on the ballot, according to both the Cook report and the Real Clear Politics average of polls. Whitmer’s slogan: “Fix the damn roads.”

In the South, gubernatorial races are toss-ups in Florida -- where Trump edged out Clinton by less than 1 percentage point -- and in Georgia, where he won by 5. Although Florida is a swing state, Georgia hasn’t elected a Democratic governor in 20 years.

Proxy Battles

Both races are proxy battles between Trump’s influence with white voters and the willingness and ability of a growing minority electorate to vote.

Republican Congressman Ron DeSantis in Florida and Secretary of State Brian Kemp in Georgia built campaigns around adulation of the president. DeSantis ran ads showing his 2-year-old daughter building Trump’s wall. Kemp’s featured a pickup truck for rounding up “illegals.” Neither was expected to win their primaries, but did after an endorsement from Trump.

Their opponents are black Democrats -- Tallahassee Mayor Andrew Gillum and Stacey Abrams, the former minority leader in the Georgia House who is vying to become the first black female governor in U.S. history. Both are hoping a new electorate of minorities and the young will help them win.

Gillum stands to gain from a growing Puerto Rican population in Florida. While Georgia remains a Republican-dominated state, Abrams could benefit from blacks moving back to the South and a growing immigrant population, said Andra Gillespie, a political scientist at Emory University.

Abrams may also benefit from women’s votes.

Of the record 16 women running for governor, 10 are Democrats vying for Republican-held seats. At least five have a shot, according to the Cook report. Democrats Michelle Grisham in New Mexico and Michigan’s Whitmer are on track to win. Abrams, Laura Kelly in Kansas and Janet Mills in Maine are in races too close to call.

Evidence that women are motivated began with Trump’s inauguration, when hundreds of thousands of them marched on Washington in protest. Next, the Me Too movement took off, revealing sexual harassment at the highest levels of business, entertainment and politics. Then a national audience watched Supreme Court nominee (now Justice) Kavanaugh be accused on national TV of a sexual assault in high school.

The last time a Supreme Court nominee was accused of sexual misbehavior was 1991, when senators grilled Anita Hill over her harassment allegations against Clarence Thomas.

The following year, voters sent a record 47 women to the House and tripled the number of female senators.